Physiological sensor pod with reset circuit

ABSTRACT

A physiologic sensor pod comprises a housing, and first and second electrodes on a bottom surface of the housing and spaced apart from one another. Within the housing is a battery, a battery charging circuit, an electrocardiogram (ECG) sensor circuit powered by the battery and adapted to sense an ECG signal, and a reset detection circuit. The battery charging circuit is adapted to charge the battery when the first and second electrodes of the physiologic sensor pod are placed in contact with first and second electrical contacts of a charging unit. The ECG sensor circuit is adapted to obtain an ECG signal while the first and second electrodes are placed against a user&#39;s chest. The reset detection circuit is adapted to output a reset signal, which causes the physiologic sensor pod to be reset, when a voltage between the first and second electrodes is greater than a reset threshold level.

PRIORITY CLAIM

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/099,929, filed Jan. 5, 2015, which is incorporated herein byreference.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A, 1B and 1C are, respectively, perspective, side and rear viewsof a physiological sensor pod according to an embodiment of the presenttechnology.

FIG. 2A illustrates a wrist band including an opening into which thephysiological sensor pod introduced in FIGS. 1A, 1B and 1C can beinserted.

FIG. 2B illustrates the wrist band of FIG. 2A with the sensor podintroduced in FIGS. 1A, 1B and 1C inserted within the opening of thewrist band.

FIG. 3 depicts an example block diagram of electrical components thatare located within the housing of the physiological sensor podintroduced in FIGS. 1A, 1B and 1C, according to an embodiment.

FIG. 4 illustrates additional details of the switch circuitry and sensorcircuitry introduced in FIG. 3, according to an embodiment.

FIGS. 5A and 5B are, respectively, perspective and top views of thecharging unit that is used to charge the sensor pod introduced in FIGS.1A, 1B and 1C, according to an embodiment.

FIG. 6 provides details of a reset detection circuit of the sensor pod,according to an embodiment.

FIGS. 7A, 7B and 7C illustrate an elastic ring that can be attached toan article of apparel or clothing, and used to selectively attach asensor pod to the article of apparel or clothing, according to anembodiment.

FIG. 8A illustrates the sensor pod, introduced in FIGS. 1A, 1B and 1C,attached to a tight fitting shirt, according to an embodiment.

FIG. 8B illustrate two of the sensor pods, introduced in FIGS. 1A, 1Band 1C, attached to a pair of socks, according to an embodiment.

FIG. 8C illustrates the sensor pod(s), introduced in FIGS. 1A, 1B and1C, attached to an arm band, according to an embodiment.

FIG. 8D illustrates the sensor pod, introduced in FIGS. 1A, 1B and 1C,attached to a headband.

FIG. 8E illustrates the sensor pod, introduced in FIGS. 1A, 1B and 1C,attached to a swim cap.

FIG. 9 illustrates the sensor pod, introduced in FIGS. 1A, 1B and 1C,hanging from a necklace in a similar manner that a pendant hangs from anecklace.

FIG. 10 illustrates the sensor pod, introduced in FIGS. 1A, 1B and 1C,attached to a head mounted display device.

FIG. 11 illustrates the sensor pod, introduced in FIGS. 1A, 1B and 1C,attached to a helmet.

FIGS. 12A, 12B and 12C illustrates a lapel adaptor that is configured tobe selectively attached with or to the sensor pod, introduced in FIGS.1A, 1B and 1C, to enable the sensor pod to be clipped to a lapel, ashirt pocket, a pant pocket, or the like.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings that form a part hereof, and in which is shown byway of illustration specific illustrative embodiments. It is to beunderstood that other embodiments may be utilized and that mechanicaland electrical changes may be made. The following detailed descriptionis, therefore, not to be taken in a limiting sense. In the descriptionthat follows, like numerals or reference designators will be used torefer to like parts or elements throughout. In addition, the first digitof a reference number identifies the drawing in which the referencenumber first appears.

FIGS. 1A, 1B and 1C are, respectively, perspective, side and rear viewsof a physiological sensor pod 100 according to an embodiment of thepresent technology. The physiologic sensor pod 100 can be moresuccinctly referred to as a sensor pod 100, or can be referred to moregenerally as a sensor device 100, a user-wearable device 100, or simplya device 100. The sensor pod 100 is shown as including a housing 102having a top surface 104, a bottom surface 114 and a peripheral surface110 extending between the top surface 104 and the button surface 114.The housing 102 also includes a groove 112 within and extending aboutthe peripheral surface 110. A battery, and electronic circuitry,including, but not limited to, a processor, memory, a wirelessinterface, switch circuitry, and a battery charging unit are locatedwithin the housing 102, as will be described in additional detail below.A majority of the housing 102 can be made of a plastic, a carboncomposite, aluminum or some other metal, but is not limited thereto.

Where one or more light emitting elements and/or one or more lightdetectors are located within the housing 102, and the material of whicha majority of the housing 102 is made is not light transmissive, thehousing can include light transmissive windows (e.g., made of a clear orother light transmissive material) that allows light to enter and/orexit through the housing windows. The housing 102 can be made in twoparts (e.g., a top part and a bottom part) that are connected togetherto encase the battery and electronic circuitry of the sensor pod 100.Where the housing 102 is made in two parts, the two parts can beprimarily made of the same material, or of different materials.

In accordance with specific embodiments, the sensor pod 100 canwirelessly communicate with a base station (e.g., 352 in FIG. 3), whichcan be a mobile phone, a tablet computer, a personal data assistant(PDA), a laptop computer, a desktop computer, or some other computingdevice that is capable of performing wireless communication. Morespecifically, the sensor pod can include a wireless interface thatenables it to communicate with and sync with a base station. The basestation can, e.g., include a health and fitness software applicationand/or other applications, which can be referred to as apps. The sensorpod 100 can upload data obtained by the sensor pod 100 to the basestation, so that such data can be used by a health and fitness softwareapplication and/or other apps stored on and executed by the basestation.

Referring specifically to FIG. 1A, the top surface 104 of the housing102 includes a top electrode 106 c. In the embodiment shown, the topsurface 104 of the housing 102 includes a goal indicator 107, which isshown as comprising a plurality of individually activatable lightemitting elements arranged in a semicircle. The light emitting elementsof the goal indicator 107 are preferably located within the housing 102,but are viewable through the top surface 104 of the housing 102. The topsurface 104 of the housing 102 further includes a plurality of modeindicator icons 108 a, 108 b, 108 c and 108 d, which are used toindicate the present operational mode of the sensor pod 100. The modeindicator icons are shown as including a calories burned icon 108 a, awalking icon 108 b, a running icon 108 c and a heart icon 108 d. Lightemitting elements within the housing 102, below the mode indicator icons108 a, 108 b, 108 c and 108 d, can selectively emit light to illuminateone of the icons to indicate the mode in which the sensor pod 100 isoperating. A user, through use of a base station (e.g., 352 in FIG. 3),can select the mode, or the sensor pod 100 or base station may selectthe mode based on data obtained from various sensors, algorithms, appsand/or the like. Although not shown, the housing 102 of the sensor pod100 can optionally include a digital display that can be used, e.g., todisplay the time, date, day of the week and/or the like, and can also beused to display activity and/or physiological metrics, such as, but notlimited to, heart rate (HR), heart rate variability (HRV), caloriesburned, steps taken, distance walked and/or run, and/or sleep metrics.

The housing 102, and more generally the sensor pod 100, can optionallyalso include an outward facing ambient light sensor (ALS) 105, which canbe used to detect ambient light, and thus, can be useful for detectingwhether it is daytime or nighttime, as well as for other purposes. Wherethe sensor pod 100 includes an ALS 105, the ALS can be placed behind alight transmissive window in the upper surface of the housing 102. Suchan ALS 105 can include one or more photodetector, each of which can be aphotoresistor, photodiode, phototransistor, photodarlington or avalanchephotodiode, but is not limited thereto.

Referring now to FIG. 1C, the bottom surface 114 of the housing 102 isshown as including a pair of spaced apart electrodes 106 a and 106 b,and plurality of light transmissive windows 116 for one or more lightemitting elements and one or more light detecting elements of aphotoplethysmography (PPG) sensor, discussed in more detail below.Additionally, the bottom surface of the housing 102 is shown asincluding a thermally conductive metal contact 118 for a skintemperature sensor, also discussed in more detail below. The thermallyconductive metal contact 118 can be made of aluminum or copper, but isnot limited thereto. Exemplary electrical components and modules thatcan be included within the housing 102 of the sensor pod 100 are shownin and described below with reference to FIG. 3.

In accordance with an embodiment, the housing 102 is water tight andwater proof, or at least water resistant. More generally, the sensor pod100 is water tight or water resistant so that it can get wet and stilloperate. In accordance with an embodiment, to increase a probabilitythat the sensor pod 100 remains water tight, the sensor pod 100 isdesigned such that once it is manufactured its housing 102 is notintended to be opened. For example, the housing 102 can be hermeticallysealed. Accordingly, in such an embodiment the battery (e.g., 310 inFIGS. 3 and 4) is not replaceable, but rather, is only rechargeable.This also means that the battery cannot be temporarily removed andreplaced to reset the sensor pod 100 in the event that the sensor pod100 gets stuck in an operational loop, crashes or otherwisemalfunctions. Further, to increase a probability that the sensor pod 100remains water tight, in accordance with an embodiment there is/are noactionable buttons on the sensor pod 100. In such an embodiment, thereis no button on the sensor pod 100 that can be used to reset the sensorpod 100 if it gets stuck in an operational loop, crashes or otherwisemalfunctions. Accordingly, in accordance with an embodiment, a resetbutton (e.g., 540 in FIGS. 5A and 5B) is instead located on a chargingunit (e.g., 500 in FIGS. 5A and 5B) that is used to charge the battery(e.g., 310 in FIGS. 3 and 4) of the sensor pod 100, and the sensor pod100 is configured to detect when the reset button on the charging unitis activated, as will be described in additional detail below withreference to FIGS. 5A, 5B and 6.

FIG. 2A illustrates a wrist band 202 that includes an opening 204 intowhich the groove 112 of the sensor pod 100 fits to secure sensor pod 100in place. FIG. 2B illustrates the wrist band 202 with the sensor pod 100secured within the opening 204. The sensor pod 100 can alternatively beplaced in a similar opening in a chest strap, headband, swim cap, armband, or some other user wearable band, strap, article of apparel ordevice. For example, a chest strap that is intended to strap the sensorpod 100 to a person's chest may resemble the wrist band 202 shown inFIGS. 2A and 2B, but would be longer in length to enable the strap tofit around a person's chest. In still other embodiments, the sensor pod100 can be placed into a pocket within a sock or tight fitting shirt(e.g., a bicycle shirt) or other article of apparel or clothing thatincludes a pocket for the sensor pod. Such a pocket can include anopening that enables the backside of the sensor pod, which includeswindows for a PPG or other optical sensor, electrodes or other sensorelements, to contact the wearer's skin to thereby enable the sensor(s)to operate properly. The opening in the pocket can also enable thegroove 112 in the sensor pod 100 to be snapped into a correct positionand held in place against a user's skin. The sensor pod 100 canalternatively be placed in an opening, slot and/or pocket in a helmet(e.g., a bicycle, motorcycle, skateboard, football, baseball, hockey,snowboard or ski helmet) or other headwear (e.g., a beanie, a baseballcap or any other type of hat). The sensor pod 100 may alternatively beplaced in an opening, slot and/or pocket in a pair of glasses or a headmounted display (HMD) that positions the back surface 114 of the sensorpod 100 against a user's temple.

FIG. 3 depicts a block diagram of electrical components 300 of thesensor pod 100, according to an embodiment, which are located within thehousing 102 of the sensor pod 100. More specifically, the componentswithin the dashed block labeled 300 are exemplary electrical componentsof the sensor pod 100, which are powered by the battery 310. Referringto FIG. 3, the sensor pod 100 is shown as including a microcontroller302 that includes a processor 304, memory 306 and a wireless interface308. It is also possible that the memory 306 and wireless interface 308,or portions thereof, are external the microcontroller 302. Otherelectronic components 300 of the sensor pod 100 can include, but are notlimited to, a battery charging circuit 340, sensor circuitry 330, atemperature sensor circuit 344, a driver circuit 332, a light detectorcircuit 338, a motion sensor 342, a photoplethysmography (PPG) sensor333 and the optional ALS 105. It is also possible that electroniccomponents 300 include more or less components than shown. The battery310 is used to power the various components of the sensor pod, and abattery charger circuit 340 is used to charge the battery 310. While notspecifically shown, the sensor pod 100 can also include one or morevoltage regulators that are used to step-up and or step-down the voltageprovided by the battery 310 to appropriate levels to power the variouscomponents of the sensor pod 100. The microcontroller 302, or theprocessor 304 thereof, receives signals from the various sensors andsensor circuits, or more generally, from the various circuitry.

At the left in FIG. 3 are small rectangular blocks that schematicallyrepresent the electrodes 106 a, 106 b and 106 c and the temperaturesensor contact 118, introduced above in the discussion on FIGS. 1A and1C. The electrodes 106 a, 106 b and 106 c can be referred tocollectively as electrodes 106, or individually as an electrode 106. Forsimplicity, in FIG. 3 the electrode 106 c is shown as being next to theelectrodes 106 a and 106 b. However, as can be appreciated from FIGS. 1Aand 1C, the electrode 106 c is remotely located relative to theelectrodes 106 a and 106 b. More specifically, the electrodes 106 a and106 b are located on the bottom surface 114 of the housing 102, as shownin FIG. 1C, and the electrode 106 c is located on the top surface 104 ofthe housing 102, as shown in FIG. 1A. Alternatively, the electrode 106 ccan be located on an upper portion of the peripheral surface 110 of thehousing 102, so long as it does interfere with the groove 112 and isaccessible (e.g., can be touched by a user's finger) when the sensor pod100 is inserted within an opening in a wrist band (e.g., 202 in FIGS. 2Aand 2B), chest band or other apparel that enables a user to wear thesensor pod 100. More generally, FIG. 3 is not intended to show theprecise locations of the various sensors, electrodes, contact,electrical components, windows, etc. of the sensor pod 100.

Also shown at the left in FIG. 3 is a block representing the window(s)116 for a light source 334 and a light detector 336 of aphotoplethysmography (PPG) sensor 333. The PPG sensor 333 includes thelight source 334 that is driven by a driver circuit 332, and the lightdetector 336 whose output is provided to a light detector circuit 338.The driver circuit 332 can be controlled by the microcontroller 302 orthe processor 304 thereof. The driver circuit 332 can include, e.g., acurrent source and a switch that selectively provides the currentproduced by the current source to the light source 304. An output of thelight detector circuit 338 can be provided to the microcontroller 302 orthe processor 304 thereof. The light source 334 can include one or morelight emitting elements, each of which can be a light emitting diode(LED), incandescent lamp or laser diode, but is not limited thereto.While it is preferred that the light source 334 emit infrared (IR)light, because the human eye cannot detect IR light, the light source334 can alternatively produce light of other wavelengths. The lightdetector 336 can include one or more photodetectors (also referred to aslight detecting elements), each of which can be a photoresistor,photodiode, phototransistor, photodarlington or avalanche photodiode,but is not limited thereto. In accordance with an embodiment, the lightsource 334 includes a single IR LED, and the light detector 336 includesfour photodiodes arranged around the single IR LED. For example,referring briefly back to FIG. 1C, the center one of the windows 116 canallow light to be emitted by the single IR LED, and the four otherwindows 116 surrounding the center window can allow reflected/scatteredlight to be incident of the four photodiodes that surround the single IRLED.

Referring again to FIG. 3, the light source 334 is selectively driven bythe driver circuit 332 to emit light. When the light source 334 emitslight a portion of the emitted light is reflected or backscattered bypatient tissue, and reflected/backscattered light is received by thelight detector 336. In this manner, changes in reflected light intensityare detected by the light detector 336, which outputs a PPG signalindicative of the changes in detected light, which are indicative ofchanges in blood volume. The light detector circuit 338 can, e.g.,convert the PPG signal output by the light detector 336 from a currentsignal to a voltage signal, and filter and/or amplify the PPG signal.Additionally, the PPG signal can be converted to a digital signal usingan analog-to-digital converter (ADC), if the PPG signal is to beanalyzed in the digital domain. Such an ADC can be part of the lightdetector circuit 338, part of the microcontroller 302, are independentthereof. Each cardiac cycle in the PPG signal generally appears as apeak, thereby enabling the PPG signal to be used to detect peak-to-peakintervals, which can be used to calculate heart rate (HR) and heart ratevariability (HRV). In accordance with certain embodiments, the lightsource 334 emits light of two different wavelengths that enablesnon-invasive monitoring of arterial oxygen saturation using pulseoximetry techniques.

The sensor pod 100 is also shown as including a motion sensor 342. Inaccordance with an embodiment the motion sensor 342 is an accelerometer.The accelerometer can be a three-axis accelerometer, which is also knownas a three-dimensional (3D) accelerometer, but is not limited thereto.The accelerometer may provide an analog output signal representingacceleration in one or more directions. For example, the accelerometercan provide a measure of acceleration with respect to x, y and z axes.The motion sensor 342 can alternatively be a gyrometer, which provides ameasure of angular velocity with respect to x, y and z axes. It is alsopossible that the motion sensor 342 is an inclinometer, which provides ameasure of pitch, roll and yaw that correspond to rotation angles aroundx, y and z axes. It is also possible the sensor pod 100 includesmultiple different types of motion sensors, some examples of which werejust described. Depending upon the type(s) of motion sensor(s) used,such a sensor can be used to detect the posture of a portion of a user'sbody (e.g., a wrist or chest) on which the sensor pod 100 is being worn.The output(s) of the motion sensor 342 can be provided to themicrocontroller 302 or the processor 304 thereof.

A block labeled sensor circuitry 330 is used to generally refer to thevarious sensor circuits (discussed in more detail below) that can beselectively connected, by switch circuitry 328, to various differentcombinations of the electrodes 106 a, 106 b and 106 c. For example, aswill be described in more detail below with reference to FIG. 4, thesensor circuitry 330 can include one or more electrocardiogram (ECG)sensor circuit, a bioimpedance analysis (BIA) sensor circuit, and acapacitive sensor circuit, but is not limited thereto. The temperaturesensor contact 118 is shown as being connected to the temperature sensorcircuit 344.

The wireless interface 308 can wireless communicate with a base station(e.g., 352), which as mentioned above, can be a mobile phone, a tabletcomputer, a PDA, a laptop computer, a desktop computer, or some othercomputing device that is capable of performing wireless communication.The wireless interface 308, and more generally the sensor pod 100, cancommunicate with a base station 352 using various different protocolsand technologies, such as, but not limited to, Bluetooth™, Wi-Fi, ZigBeeor ultrawideband (UWB) communication. In accordance with an embodiment,the wireless interface 308 comprises telemetry circuitry that include aradio frequency (RF) transceiver electrically connected to an antenna(not shown), e.g., by a coaxial cable or other transmission line. Suchan RF transceiver can include, e.g., any well-known circuitry fortransmitting and receiving RF signals via an antenna to and from an RFtransceiver of a base station 352.

FIG. 4 will now be used to describe additional details of the switchcircuitry 328 and sensor circuitry 330 introduced in FIG. 3. Referringto FIG. 4, the sense circuitry 330 is shown as including a 1st ECGsensor circuit 402, a 2nd ECG sensor circuit 404, a galvanic skinresistance (GSR) sensor circuit 406, a bioimpedance analysis (BIA)sensor circuit 408 and a capacitive sensor circuit 410. As can beappreciated from FIG. 4, the switch circuitry 328 enables these varioussensor circuits, of the sensor circuitry 330, to share the sameelectrodes 106. In an embodiment, the microcontroller 302 (or some othercontroller) produces one or more switch control signals that selectivelycontrol how and when individual ones (or subsets of) the electrodes 106is/are connected to the various inputs of the sensor circuits 402, 404,406, 408 and 410. As can also be appreciated from FIG. 4, the switchcircuitry 328 can be used to selectively connect the two bottomelectrodes 106 a and 106 b to the battery charging circuit 340. Moregenerally, the switch circuitry 328 enables two (or more) of the sameelectrodes 106 to be used, albeit at different times, by the batterycharging circuit 340 and one or more sensor circuits (e.g., 402, 404,406, 408 and/or 410). Also shown in FIG. 4 is a reset detection circuit420, additional details of which are discussed below with reference toFIG. 6.

In FIG. 4, the switch circuitry 328 is schematically shown as includingswitches 402 a, 402 b, 402 c, 402 d, 402 e, 402 f and 402 g. Theswitches can be implemented using transistor types of switches, but arenot limited thereto. For example, in accordance with an embodiment, theswitches 402 a are implemented using reed switches.

When the switches 402 a are closed, also referred to as activated, theelectrodes 106 a and 106 b are connected to the battery charging circuit340. When the switches 402 b are closed, the electrodes 106 a and 106 bare connected to the 1^(st) ECG sensor circuit 402. The 1^(st) ECGsensor circuit 402 is used to sense an ECG signal between the two bottomelectrodes 106 a and 106 b when the electrodes 106 a and 106 b arecontact with a person's chest. When the two bottom electrodes 106 a and106 b of the sensor pod 100 are against another portion of a person'sbody (e.g., a person's wrist), instead of against a person's chest, anECG signal cannot be sensed between the two bottom electrodes 106 a and106 b.

When the switches 402 c are closed, the electrodes 106 a and 106 c areconnected to the 2^(nd) ECG sensor circuit 402. The 2^(nd) ECG sensorcircuit 404 is used to sense an ECG signal between at least one of thebottom electrodes 106 a, 106 b that is in contact with a person's skin(e.g., on their wrist) and the top (or side) electrode 106 c that is incontact with another portion of the person's skin (e.g., a finger on theopposite hand). In other words, an ECG signal can be sensed when one (orboth) of the electrodes 106 a, 106 b are in contact with a user's arm(or other body part) and the electrode 106 c is in contact with a user'sfinger on their other arm, in which case a circuit is completed thatextends across the user's chest cavity that includes their heart.

While the 2^(nd) ECG sensor circuit 404 is being used, both of thebottom electrodes 106 a and 106 b can be shorted to one another by theswitch 402 g (such that they function as one large electrode) andconnected to one input of the 2^(nd) ECG sensor circuit 404, while theother input of the 2^(nd) ECG sensor circuit 404 is connected to the top(or side) electrode 106 c. Alternatively, while the 2^(nd) ECG sensorcircuit 404 is being used, only one of the bottom electrodes 106 a or106 b is connected to one input of the 2^(nd) ECG sensor circuit 404,while the other input of the 2^(nd) ECG sensor circuit 404 is connectedto the top (or side) electrode 106 c. In other words, one of the bottomelectrodes 106 a or 106 b may not be connected the 2^(nd) ECG sensorcircuit 404. More specifically, while the switches 402 c are closed, theswitch 402 g can optionally also be closed, in which case the electrodes106 a and 106 b are shorted (i.e., connected) together and function asone larger single electrode.

The 1^(st) and 2^(nd) ECG sensor circuits 402 and 404 can each includeone or more low power, precision amplifiers with programmable gainand/or automatic gain control, bandpass filtering, and a thresholddetection circuit, as known in the art, to selectively sense an ECGsignal of interest. In an embodiment, the maximum gain provided by the2^(nd) ECG sensor circuit 402 is greater than the maximum gain providedthe 1^(st) ECG sensor circuit 404. In accordance with an embodiment, the1^(st) and 2^(nd) ECG sensor circuits 402 and 404 share at least somecircuitry. In an embodiment, there is only one ECG sensor circuit thatis used regardless of whether an ECG signal is being sensed between thetwo bottom electrodes 106 a and 106 b, or between one (or both) of thebottom electrodes 106 a, 106 b and the top (or side) electrode 106 c. Inthe embodiment where there is only one ECG sensor circuit, the switchcircuitry 328 connects each of the bottom electrodes 106 a and 106 b toa different one of the two inputs of the ECG sensor circuit when thesensor pod 100 is placed against a person's chest; and the switchcircuitry 328 connects the one (or both) of the bottom electrodes 106 a,106 b to the one of the inputs of the ECG sensor circuit, and connectsthe top (or side) electrode 106 c to the other input of the ECG sensorcircuit, when the sensor pod 100 is placed against another portion ofthe user's body, besides their chest, such as on a person's wrist.

When the switches 402 d are closed, the electrodes 106 a and 106 b areconnected to the GSR sensor circuit 406. The GSR sensor circuit 406 isused to senses a galvanic skin resistance between a pair of theelectrode 106 (e.g., the electrodes 106 a and 106 b) that are in contactwith a person's skin. The galvanic skin resistance measurement will berelatively low when a user is wearing the sensor pod 100 such that theelectrodes 106 a and 106 b are against their skin. By contrast, thegalvanic skin resistance measurement will be very high when theelectrodes 106 a and 106 b are not in contact with the user's skin. Thegalvanic skin resistance measurement, which can also be referred to as agalvanic skin response, may also vary based on levels perspiration.

When the switches 402 e are closed, the electrodes 106 a and 106 b areconnected to the BIA sensor circuit 408. The BIA sensor circuit 408 isused to measure impedance, at one or more frequencies, between a pair ofthe electrodes 106 (e.g., the electrodes 106 a and 106 b) that are incontact with a person's skin.

When the switch 402 f is closed, the electrode 106 a is connected to thecapacitive sensor circuit 410. The switch 402 g can also be closed, inwhich case the electrodes 106 a and 106 b are shorted together and areconnected to the capacitive sensor circuit 410. The capacitive sensorcircuit 420 is used to measure a capacitance between one (or both) ofthe electrode 106 a, 106 and a person's skin, which information can beused, e.g., to determine whether or not the sensor pod 100 is in contactwith a person's skin. In accordance with an embodiment, one (or both) ofthe electrode 106 a, 106 function as one plate of a capacitor, while anobject (e.g., a user's wrist or chest) functions as the other plate ofthe capacitor. The capacitive sensor circuit 420 can indirectly measurecapacitance, and thus proximity, e.g., by adjusting the frequency of anoscillator in dependence on the proximity of an object relative to theelectrode(s) 106 connected to the capacitive sensor circuit 420, or byvarying the level of coupling or attenuation of an AC signal independence on the proximity of an object relative the electrode(s) 106connected to the capacitive sensor circuit 420.

In accordance with an embodiment, the switches 402 a are implemented asswitches that are normally closed, while the other switches (e.g., theswitches 402 b-402 g) are implemented as switches that are normallyopen. By having the switches 402 a be normally closed, the electrodes106 a and 106 b are by default connected to the battery charging circuit340. This way, if a voltage generated by the battery 310 drops so lowthat it cannot provide sufficient power to the microcontroller 302 (oranother switch controller) to control the switch circuitry 328, then thesensor pod 100 is in a state that the battery 310 can be charged. Moregenerally, the switch circuitry 328 is, by default, in a configurationthat connects the electrodes 106 a and 106 b to the battery chargingcircuit 340, so that if an energy level of the battery 310 isinsufficient to power the microcontroller 302 and/or the switchcircuitry 328 the battery 310 can still be charged using a charging unit(e.g., 500 in FIGS. 5A and 5B).

As mentioned above, in accordance with an embodiment the switches 402 athat are used to selectively connect the electrodes 106 a and 106 b tothe battery charging circuit 340 are implemented as reed switches. Areed switch is an electrical switch operated by a magnetic field. Inother words, the switches 402 a can be magnetically actuated reedswitches. Where the switches 402 a are implemented as reed switches, thereed switches can be open in their default state, and physically locatedwithin the sensor pod 100 such that when the sensor pod 100 is sittingon/against the charging unit (e.g., 500 in FIGS. 5A and 5B) one or moremagnets (e.g., 516 a and 516 b in FIGS. 5A and 5B) of the charging unitcause the reed switches to switch to a closed (i.e., activated) state,which causes the electrodes 106 a and 106 b of the sensor pod 100 to beconnected to the battery charging circuit 340 of the sensor pod 100. Inother words, referring briefly to FIGS. 5A and 5B, when the sensor pod100 is placed on/against the charging unit 500, the magnet(s) 516 aand/or 516 b can cause the switches 402 a, implemented as reed switches,to connect the electrodes 106 a and 106 b to the battery chargingcircuit 340 so that the battery 310 can be charged.

Referring again to FIG. 3, the sensor pod 100 is shown as includingvarious detectors or trackers, including an on-body detector 312, asleep detector 314, a sleep metric detector 316, a heart rate (HR)detector 318, a heart rate variability (HRV) detector 320, an activitydetector 322, a calorie burn detector 324 and a time and date tracker326. The various detectors and trackers may communicate with oneanother, as will be explained below. Each of these detectors andtrackers 312, 314, 316, 318, 320, 322, 324 and 326 can be implementedusing software, firmware and/or hardware. It is also possible that someof these detectors and trackers are implemented using software and/orfirmware, with others implemented using hardware. Other variations arealso possible. In accordance with a specific embodiments, each of thesedetectors or trackers 312, 314, 316, 318, 320, 322, 324 and 326 isimplemented using software code that is stored in the memory 306 and isexecuted by the processor 304. The memory 306 is an example of atangible computer-readable storage apparatus or memory havingcomputer-readable software embodied thereon for programming a processor(e.g., 304) to perform a method. For example, non-volatile memory can beused. Volatile memory such as a working memory of the processor 304 canalso be used. The computer-readable storage apparatus may benon-transitory and exclude a propagating signal.

The on-body detector 312 uses signals and/or data obtained from one ormore of the above described sensors and/or sensor circuits to determinewhether the sensor pod 100 is being worn by a user (also referred toherein as a person). For example, the on-body detector 312 can usesignals/and/or data obtained from the light source 334 and lightdetector 336 (which can collectively be referred to as a PPG sensor333), the GSR sensor circuit 406, the temperature sensor circuit 344,the capacitive sensor circuit 410 and/or the motion sensor 342 todetermine whether the sensor pod 100 is being worn by a user. Theon-body detector 312 can be used to selective operate the sensor pod 100in a low power mode when the on-body detector 312 detects that thesensor pod 100 is not being worn by a user. Additional details of theon-body detector 212 are described in U.S. patent application Ser. No.14/341,248, titled “User-Wearable Devices with Power ConservingFeatures,” which was filed Jul. 24, 2014.

The sleep detector 314 uses signals and/or data obtained from one ormore of the above described sensors to determine whether a user, who iswearing the sensor pod 100, is sleeping. For example, signals and/ordata obtained using the motion sensor 342 can be used to determine whena user is sleeping. This is because people typically move around lesswhen sleeping compared to when awake. For another example, if the sensorpod 100 includes an outward facing ambient light sensor (ALS) (e.g., 105in FIG. 1A) then signals and/or data obtained using the outward facingALS can additionally or alternatively be used to determine when a useris sleeping. This is because people typically sleep in a relatively darkenvironment with low levels of ambient light. Additionally, if theuser's arm posture can be detected from the motion sensor 342, theninformation about arm posture can also be used to detect whether or nota user is sleeping. The sleep detector 314 can also be used to detectwhen a user, who is wearing the sensor pod 100, wakes up, as well aswhen the user is awake.

The sleep metric detector 316 uses signals and/or data obtained from oneor more of the above described sensors and/or other detectors andtrackers to quantify metrics of sleep, such as total sleep time, sleepefficiency, number of awakenings, and estimates of the length orpercentage of time within different sleep states, including, forexample, rapid eye movement (REM) and non-REM states. The sleep metricdetector 316 can, for example, use signals and/or data obtained from themotion sensor 342 and/or from the HR detector 318 to distinguish betweenthe onset of sleep, non-REM sleep, REM sleep and the user waking fromsleep. One or more quality metric of the user's sleep can then bedetermined based on an amount of time a user spent in the differentphases of sleep. Such quality metrics can be uploaded to a base station(e.g., 352) for display and/or further analysis. Additionally, oralternatively, if the sensor pod 100 included a digital display, suchmetrics can be displayed on such a digital display.

The HR detector 318 can use signals and/or data obtained from the PPGsensor 333 to detect HR. For example, the PPG sensor 333 can be used toobtain a PPG signal from which peak-to-peak intervals can be detected,which can also be referred to as beat-to-beat intervals. Additionally,or alternatively, beat-to-beat intervals can be determined from an ECGsignal obtained using an ECG sensor circuit (e.g., 402 or 404 in FIG. 4)by measuring the time interval between R-waves or other features of theECG signal. The beat-to-beat intervals, which are intervals betweenheart beats, can be converted to HR using the equationHR=(1/beat-to-beat interval)*60. Thus, if the beat-to-beat interval=1sec, then HR=60 beats per minute (bpm); or if the beat-to-beatinterval=0.6 sec, then HR=100 bpm. In an embodiment, the HR detector 318can measure the beat-to-beat intervals of a PPG signal, and also measurethe beat-to-beat intervals of an ECG signal, and use an average of thetwo types of beat-to-beat intervals to detect HR. In another embodiment,there can be a determination of whether a PPG signal or an ECG signalhas a greater to signal-to-noise ratio (SNR), and which ever one of thePPG and ECG signals has a greater SNR can be used by the HR detector 318to detect HR. The user's HR can be uploaded to a base station (e.g.,352) for display and/or further analysis. Additionally, oralternatively, if the sensor pod 100 included a digital display, HR orinformation indicative can be displayed on such a digital display.

The HRV detector 320 can use signals and/or data obtained from the PPGsensor 333 and/or one of the ECG sensor circuits 402 or 404 to detectHRV. For example, in the same manner as was explained above,beat-to-beat intervals can be determined from a PPG signal obtainedusing the PPG sensor 333. Additionally, or alternatively, beat-to-beatintervals can be determined from an ECG signal obtained using an ECGsensor circuit (e.g., 402 or 404 in FIG. 4) by measuring the timeinterval between R-waves or other features of the ECG signal. HRV can bedetermined by calculating a measure of variance, such as, but notlimited to, the standard deviation (SD), the root mean square ofsuccessive differences (RMSSD), or the standard deviation of successivedifferences (SDSD) of a plurality of consecutive beat-to-beat intervals.Alternatively, or additionally, an obtained PPG signal and/or ECG signalcan be converted from the time domain to the frequency domain, and HRVcan be determined using well known frequency domain techniques. In anembodiment, the HRV detector 320 can measure the beat-to-beat intervalsof a PPG signal, and also measure the beat-to-beat intervals of an ECGsignal, and use an average of the two types of beat-to-beat intervals todetect HRV. In another embodiment, there can be a determination ofwhether a PPG signal or an ECG signal has a greater to signal-to-noiseratio (SNR), and which ever one of the PPG and ECG signals has a greaterSNR can be used by the HRV detector 320 to detect HRV. The user's HRVcan be uploaded to a base station (e.g., 352) for display and/or furtheranalysis. Additionally, or alternatively, if the sensor pod 100 includeda digital display, HRV or information indicative thereof can bedisplayed on such a digital display.

The activity detector 322 can determine a type and amount of activity ofa user based on information such as, but not limited to, motion dataobtained using the motion sensor 342, heart rate as determined by the HRdetector 318, skin temperature as determined by the skin temperaturesensor 340, and time of day. The activity detector 322 can use motiondata, obtained using the motion sensor 342, to determine the number ofsteps that a user has taken with a specified amount of time (e.g., 24hours), as well as to determine the distance that a user has walkedand/or run within a specified amount of time. Activity metrics can beuploaded to a base station (e.g., 252) for display and/or furtheranalysis. Additionally, or alternatively, if the sensor pod 100 includeda digital display, such metrics can be displayed on such a digitaldisplay. The goal indicator 107, shown in FIG. 1A, can also be used toinform a user of how close they are to reaching an activity relatedgoal, which can be a steps goal or a distance goal.

The calorie burn detector 324 can determine a current calorie burn rateand an amount of calories burned over a specified amount of time basedon motion data obtained using the motion sensor 342, HR as determinedusing the HR detector 318, and/or skin temperature as determined usingthe skin temperature sensor 340. A calorie burn rate and/or an amount ofcalories burned can uploaded to a base station (e.g., 252) for displayand/or further analysis. Additionally, or alternatively, if the sensorpod 100 included a digital display, such information can be displayed onsuch a digital display. The goal indicator 107, shown in FIG. 1A, canalso be used to inform a user of how close they are to reaching acalories burned goal.

The time and date tracker 326 can keep track of the time of day, date,and/or the like. The time and date tracker 326 of the sensor pod 100 canbe synced with a similar tracker of the base station 352. The time anddata tracker 326 can provide time of day and date information to theother detectors described herein and/or can be used to date and/or timestamp collected data.

The sensor pod 100 can include less modules than shown in FIG. 3, moremodules than show and/or alternative types of modules. For example, thesensor pod 100 can also include a body water content module and/or abody fat content module that calculates the user's body water contentand/or body fat percentage based on measurements obtained using the BIAsensor circuit 408. Alternatively, the base station 352 can calculatebody water content and/or body fat content based on data obtained usingthe BIA sensor circuit 408 of the sensor pod 100. For another example,the sensor pod 100 can include a stress module that estimates a user'sstress level based on measures obtained using the GSR sensor circuit406, one of the ECG sensor circuits 402, 404 and/or the skin temperaturesensor circuit 344. Alternatively, the base station 352 can estimate theuser's stress level based on data obtained from the GSR sensor circuit406, one of the ECG sensor circuits 402, 404 and/or the skin temperaturesensor circuit 344 of the sensor pod 100.

The sensor pod 100 can also include respiration module that determinesrespiration rate from a PPG signal obtained using the PPG sensor 333and/or from the ECG signal obtained using an ECG sensor circuit 402 or404. For another example, a blood pressure module can determine bloodpressure from PPG and ECG signals by determining a metric of pulse wavevelocity (PWV) and converting the metric of PWV to a metric of bloodpressure. More specifically, a metric of PWV can be determining bydetermining a time from a specific feature (e.g., an R-wave) of anobtained ECG signal to a specific feature (e.g., a maximum upward slope,a maximum peak or a dicrotic notch) of a simultaneously obtained PPGsignal. An equation can then be used to convert the metric of PWV to ametric of blood pressure. These are just a few examples of other typesof modules or detectors that can be included within sensor pod 100,which are not intended to be all encompassing.

Referring again to FIG. 3, the microcontroller 302, or the processor 304thereof, can determine which switches of the switch circuitry 328 toopen and close based on which mode the sensor pod 100 is operating in.For example, when the sensor pod 100 is in a HR or HRV detection mode,and the sensor pod 100 is resting against a person's chest (such thatthe electrodes 106 a and 106 b are contacting the person's skin), theswitches 402 b can be closed. For another example, when the sensor pod100 is in a HR or HRV detection mode, and the sensor pod 100 is strappedto a person's wrist (e.g., using the wrist band 202 in FIGS. 2A and 2B),then the switches 402 c (and optionally also the switch 402 g) can beclosed. For still another example, when the sensor pod 100 is in a modewhere galvanic skin resistance needs to be measured, then the switches402 c can be closed. The sensor pod 100 itself can decide when to changemodes. Alternatively, or additionally, a base station (e.g., 352) inwireless communication with the sensor pod 100 can select which mode thesensor pod 100 is operating in. As mentioned above, in accordance withan embodiment, the switches 402 a are normally closed, and the otherswitches are normally open, so that a default mode for the sensor pod100 is a battery charging mode.

FIGS. 5A and 5B are, respectively, perspective and top views of acharging unit 500 that is used to charge the sensor pod 100 inaccordance with an embodiment. The charging unit 500 is shown asincluding a housing 514 having a pair of electrical contacts 506 a and506 b. The electrical contacts 506 a and 506 b are spaced apart from oneanother and are intended to be electrically coupled to the bottomelectrodes 106 a and 106 b of the sensor pod 100, when the sensor pod100 is placed upon the charging unit 500. A cable 530 that includes anadaptor 532 (e.g., a USB adaptor) that pluggable into a power source(e.g., a computing device) to provide power to the charging unit 500.The cable 530 can alternatively include a plug having prongs that can beplugged into an electrical wall socket to provide power to the chargingunit. Other ways of providing power to the charging unit 500 are alsopossible and within the scope of embodiments described herein, as wouldbe appreciated by one of ordinary skill in the art reading thisdescription.

The charging unit 500 includes electrical circuitry within the housing514 that generates a predetermined voltage (+/− a tolerance) between theelectrical contacts 506 a and 506 b. When the electrical contacts 506 aand 506 b are in contact with the electrodes 106 a and 106 b of thesensor pod 100, the battery charging circuit 340 of the sensor pod 100is powered by the charging unit 500 and the battery 310 of the sensorpod 100 is charged. Such powering of the battery charging circuit 340,through use of a direct contact electrical coupling between theelectrical contacts 506 a and 506 b of the charging unit 500 and thebattery charging circuitry 330 of the sensor pod 100, provides forfaster and more efficient charging of the battery 310 than would bepossible if there was instead an inductive coupling between the chargingunit 500 and the battery charging circuitry 330 of the sensor pod 100.

In accordance with an embodiment, the electrical contacts 506 a and 506b are magnetic. The electrical contacts 506 a and 506 b can themselvesbe magnetic, or more likely, a magnet 516 a can be located below theelectrical contact 506 a and a magnet 516 b can be located below theelectrical contact 506 b. Magnetizing the electrical contacts 506 a and506 b (e.g., using adjacent magnets 516 a and 516 b) makes it easier fora person to correctly place the electrodes 106 a and 106 b of the sensorpod 100 against (e.g., on top of) the electrical contact 506 a and 506b, and helps keep the electrodes 106 a and 106 b of the sensor pod 100properly aligned with and against the electrical contact 506 a and 506 bduring charging of the battery 310 of the sensor pod 100. The magnets516 a and 516 b can be permanent magnets. Alternatively, the magneticforce of the magnets 516 a and 516 b can be generated using electricity,e.g., by generating an electromagnetic field.

In an embodiment, the charging unit 500 includes a light source 522 anda light detector 524, which collectively can operate as an opticalproximity detector that is used to detect when the sensor pod 100 isresting on/against the charging unit 500. In accordance with anembodiment, the charging unit 500 only generates the predeterminedvoltage (+/− a tolerance) between its electrical contacts 506 a and 506b when the charging unit detects that a sensor pod 100 is resting onand/or against the charging unit 500. There are various differenttechniques that the charging unit 500 can use to detect when that asensor pod 100 is resting on/against the charging unit 500. In oneembodiment, the light source 522 and the light detector 524 operate asan optical proximity sensor to detect whether or not a sensor pod 100 isresting on/against the charging unit 500. In other words, the chargingunit 500 can utilize the light source 522 and the light detector 524,operating as an optical proximity detector, to detect when a sensor pod100 is resting on/against the charging unit 500. The charging unit 500can alternatively use other techniques to detect when a sensor pod 100is resting on/against the charging unit 500 while also being within thescope of the embodiments described herein.

The charging unit 500 is also shown as including a reset button 540 thatcan be used to reset the sensor pod 100 while the sensor pod 100 isresting on/against the charging unit 500. The sensor pod 100 may need tobe reset, e.g., if it gets stuck in an operational loop, crashes orotherwise malfunctions. While the reset button 540 is shown as beinglocated on the side of the housing 514, the reset button 540 can belocated at a myriad of other locations. Referring briefly back to FIG.4, in accordance with an embodiment the reset detection circuit 420detects when the rest button on the charging unit 500 is activated, andin response thereto, outputs a reset signal that is provided to a resetpin of the microcontroller 302 of the sensor pod 100. Additional detailsof the operation of the reset detection circuit 420, according tospecific embodiments, are described below with reference to FIG. 6. Theinclusion of a reset button 540 on the charging unit 500 is especiallyuseful where the sensor pod 100 has no activatable buttons (and thus, nothe sensor pod 100 has no reset button) and where the housing 102 of thesensor pod 100 is not intended to be opened (and thus, the sensor pod100 cannot be reset by removing and replacing its battery 310 within itshousing 102).

FIG. 6 provides details of a reset detection circuit 420 of the sensorpod 100 according to an embodiment. In FIG. 6, the components shown tothe left of the vertical dashed line are components of the charging unit500, and the components shown to the right of the vertical dashed lineare components of the sensor pod 100. In FIG. 6, the electrodes 106 aand 106 b of the sensor pod 100 are shown as being in contact,respectively, with the electrical contacts 506 a and 506 b of thecharging unit 500. The charging unit 500 is shown as including a voltageregulator 602 that generates a first output voltage V1 or a secondoutput voltage V2, where V2 is greater than V1. In accordance withcertain embodiments, V2 is at least 20% greater than V1, V2 ispreferably at least 50% greater than V1, and even more preferably V2 isat least twice V1. In an embodiment, the voltage regulator 602 normallyproduces the first output voltage V1, which is the nominal voltage thatis used by the battery charging circuit 340 to charge the battery 310.For example, the voltage V1 can be 3.3V, but is not limited thereto. Inresponse to the reset button (e.g., 540 in FIGS. 5A and 5B) beingpressed, the voltage regulator 602 generates the second output voltageV2, which can be, e.g., 8V, but is not limited thereto. Numerous othercomponents can be included within the charging unit 500, such as, butnot limited to, a DC-DC converter, or an AC-DC converter, one of whichcan provide a voltage input to the voltage regulator 602, as would beappreciated by one or ordinary skill in the art reading this disclosure.

In accordance with certain embodiments of the present technology, thereset detection circuit 420 is adapted to output a reset signal, whichcauses the sensor pod 100 to be reset, when a voltage between theelectrodes 106 a and 106 b is greater than a reset threshold level. Inthe specific embodiment shown in FIG. 6, the reset detection circuit 420is shown as including a comparator 622 that compares a voltage V3 to areference voltage (Vref), wherein the voltage V3 is indicative of thevoltage output by the voltage regulator 602, or more generally, isindicative of the voltage between the electrical contacts 506 a and 506b of the charging unit 500. The voltage V3 can actually be equal to V1or V2, are can be stepped down versions thereof produced using theresistors R1 and R2 and/or some other circuitry. The reference voltage(Vref) is indicative of the reset threshold level.

Still referring to FIG. 6, in accordance with an embodiment the outputof the comparator 622, which will be either high or low, is the resetsignal generated by the reset detection circuit 420. When the voltage V3is less than Vref, then the output of the comparator 622 will be low.When the voltage V3 is greater the Vref, then the output of thecomparator 622 will be high. In other words, the comparator 622 outputsthe reset signal when the voltage V3 (indicative of the voltage betweenthe electrodes 106 a and 106 b) is greater than the reference voltage(Vref) (indicative of the reset threshold level). Assuming the reset pinof the microcontroller 302 is active high, this means that when V3 isgreater than Vref, the microcontroller 302 will be reset. Morespecifically, when the voltage output by the voltage regulator 602 issufficiently high to cause the voltage V3 to exceed Vref, then themicrocontroller 302, and more generally the sensor pod 100, will bereset. This is just one exemplary implementation of the reset detectioncircuit 420. For example, the inverting (−) and non-inverting (+) inputsof the comparator 622 can be swapped if the microcontroller 302 isinstead adapted to be reset in response to a low input signal beingprovided to its reset pin. For another example, the voltage V3 providedto the comparator need not be generated using the resistors R1 and R2.Rather, in an alternative embodiment, one of the inputs of thecomparator 622 can receive that actual voltage level (V1 or V2) providedby the charging unit 500 to the sensor pod 100. Other variations arealso possible, as would be appreciated by one of ordinary skill in theart reading this disclosure. In such variations, the reset detectioncircuit 420 detects when the voltage provide by the charging unit 500 isabove its nominal voltage level, and more specifically above a resetthreshold level, and interprets such a detection as an indication that areset signal should be generated to reset the sensor pod 100.

As explained above in the discussion of FIGS. 2A and 2B, the sensor pod100 can be inserting into an opening 204 in a wrist band 202, or someother band or strap, such as a headband, arm band or some other userwearable band, strap or device. As also noted above, the sensor pod 100can alternatively be placed into a pocket within a sock or tight fittingshirt (e.g., a bicycle shirt) or other article of apparel or clothingthat includes a pocket for the sensor pod 100. Such a pocket can includean opening that enables the backside of the sensor pod 100, whichincludes windows for the PPG sensor (and/or other optical sensor(s)),electrodes and/or other sensor elements, to contact the wearer's skin tothereby enable the sensor(s) to operate properly. Such an opening canalso enable the groove 112 in the sensor pod 100 to be snapped into acorrect position and held in place against a user's skin. The sensor pod100 can alternatively be placed in an opening, slot and/or pocket in ahelmet (e.g., a bicycle, motorcycle, skateboard, football, baseball,hockey, snowboard or ski helmet) or other headwear (e.g., a beanie, abaseball cap or any other type of hat). The sensor pod 100 mayalternatively be placed an opening, slot and/or pocket in a pair ofglasses or a head mounted display (HMD) that positions the back surface114 of the sensor pod 100 against a user's temple.

FIGS. 7A, 7B and 7C will now be used to explain in more detail how thesensor pod 100 can be selectively attached to an article of apparel orclothing. Referring to FIG. 7A, an elastic ring 700 is shown as beingattached to piece of fabric 720 such that an opening in the fabric isaligned with an opening 704 in the elastic ring 700. The elastic ring700 is shown as having oval or elliptical shape and generally has thesame shape as the circumferential surface 110 of the sensor pod 100. Inaccordance with an embodiment, an inner circumference 702 of the elasticring 700 is slightly smaller than the outer circumference of the groove112 in the circumferential surface 110 of the sensor pod 100. Thisenables the groove 112 in the sensor pod 100 to be snapped into theopening 704 in the elastic ring 700 and held in place, e.g., against theskin of a user wearing the article of apparel or clothing that includesthe piece of fabric 720. The elastic ring 700 can be sewn into thefabric 720 using stitches 706 made of thread or a similar material.While two rows of the stitches 706 are shown in FIGS. 7A, 7B and 7C, asingle row of stitches can be used, or more than two rows of stitchescan be used. The elastic ring 700 can be made of silicon, rubber, orsome other similar elastic material.

FIG. 7B illustrates a perspective cross-sectional view of the elasticring 700 along the dashed line BC-BC in FIG. 7A, according to anembodiment. Referring to FIG. 7B, a slit 705 extends from an outercircumference 703 of the elastic ring 700 toward, but not all the wayto, the inner circumference 702 of the elastic ring 700. A portion ofthe fabric 720 is inserted into the slit 705 and then a peripheralportion of the elastic ring 700 is sewn, by the stitches 706, to thefabric 720. Additionally, or alternatively, an adhesive can be used toattach a portion of the fabric 720 within the slit 705.

FIG. 7C illustrates a perspective cross-sectional view of the elasticring 700 along the dashed line BC-BC in FIG. 7A, according to anotherembodiment. Referring to FIG. 7C, the elastic ring 700 is shown asincluding two sub-components, including a main ring 700 a and a supportring 700 b. Both the main ring 700 a and the support ring 700 b can bemade of silicon, rubber, or some other similar elastic material.Alternatively, the support ring 700 b can be made of a more rigidmaterial, since the support ring 700 b does not need to be stretched. Ascan be appreciated from FIG. 7C, a portion of the fabric 720 is placedbetween a peripheral portion of the main ring 700 a and the support ring700 b. The peripheral portion of the main ring 700 a and the supportring 700 b are stitched together with the portion of the fabric 720therebetween to thereby attach the elastic ring 700 to the fabric 720.

FIG. 8A illustrates a tight fitting shirt 800 a having an elastic ring700 (described with reference to FIGS. 7A, 7B and 7C) attached thereto.FIG. 8A also shows the sensor pod 100 snapped into the elastic ring 700and thereby selectively attached to the shirt 800 a.

FIG. 8B illustrates a pair of socks 800 b having an elastic ring 700(described with reference to FIGS. 7A, 7B and 7C) attached thereto. FIG.8B also shows one of the sensor pods 100 snapped into the elastic ring700 in each of the socks 800 b and thereby attached to the socks 800 b.

FIG. 8C illustrates an arm band 800 c having an elastic ring 700(described with reference to FIGS. 7A, 7B and 7C) attached thereto. FIG.8C also shows one of the sensor pods 100 snapped into the elastic ring700 in the arm band 800 c and thereby attached to the arm band 800 c.FIG. 8C further illustrates that the arm band 800 c can also carry amobile phone, which as explained above, may function as a base stationfor the sensor pod 100.

FIG. 8D illustrates the sensor pod 100 attached to a headband 800 d.

FIG. 8E illustrates the sensor pod 100 attached to a swim cap 800 e.

FIG. 9 illustrates the sensor pod 100 hanging from a necklace 902, in asimilar manner that a pendant hangs from a necklace.

FIG. 10 illustrates the sensor pod 100 attached to a head worn displaydevice 1000. The sensor pod can similarly be attached to other types ofglasses.

FIG. 11 illustrates the sensor pod 100 attached to a helmet body 1100.The helmet body 1100 is shown as including a pair of connectors 1102 aand 1102 b attached to a portion of the helmet body 1100 that isintended to rest against a user's forehead. These connectors 1102 a and1102 b enable the physiologic sensor pod 100 to be selectively attachedto the helmet body 1100. An elastic ring type of connector, the same orsimilar to the elastic ring 700 described above, can be used in place ofthe pair of connectors 1102 a and 1102 b. Other types of connectors thatenable the sensor pod 100 to be selectively connected to the helmet body1100 are also possible and within the scope of the embodiments describedherein.

FIG. 12A illustrates a lapel adaptor 1200 that is configured to beselectively attached with or to the sensor pod 100 to enable the sensorpod 100 to be clipped to a lapel, a shirt pocket, a pant pocket, or thelike. The lapel adaptor 1200 includes a first portion 1201 that isadapted to be selectively attached to the sensor pod 100, a secondportion 1202, and a third portion 1203 between the first and secondportions 1201 and 1202. The third portion 1203 is adapted to enable thesecond portion 1202 to be folded toward the first portion 1201, and viceversa, and thus the third portion 1203 operates as a hinge, and thus,can be referred to as a hinge or a hinged portion 1203. The secondportion 1202 includes a pair of magnets 1206 a and 1206 b that arespaced apart from one another by approximately the same distance thatthe electrodes 106 a and 106 b are spaced apart from one another on thebottom surface 114 of the sensor pod 100. In accordance with anembodiment, the entire lapel adaptor 1200, except for the magnets 1206 aand 1206 b, is made of silicon, rubber, or some other flexible material.In accordance with another embodiment, the first portion 1201 and thethird portion 1203 of the lapel adaptor is made of silicon, rubber, orsome other flexible material, and the second portion 1202 is made of amore rigid material, such as plastic or aluminum. The magnets 1206 a and1206 b can be made of magnetic stainless steel, but are not limitedthereto. Other variations are possible and within the scope ofembodiments described herein.

The first portion 1201 of the lapel adaptor 1200 includes an elasticring 1207 having an opening 1204. The elastic ring 1207 is shown ashaving oval or elliptical shape and generally has the same shape as thecircumferential surface 110 of the sensor pod 100. In accordance with anembodiment, an inner circumference of the elastic ring 1207 is slightlysmaller than the outer circumference of the groove 112 in thecircumferential surface 110 of the sensor pod 100. This enables thegroove 112 in the sensor pod 100 to be snapped into the opening 1204 inthe elastic ring 1207 and held in place.

FIG. 12B is a perspective view of the lapel adaptor 1200 with the sensorpod 100 snapped into the opening in the elastic ring 1207 of the firstportion 1201 of the lapel adaptor 1200. FIG. 12C is a side view of thelapel adaptor 1200 with the sensor pod 100 snapped into the opening inthe elastic ring 1207 of the first portion 1201 of the lapel adaptor1200, with the second portion 1202 folded toward the first portion 1201such that the magnets 1206 a and 1206 b are aligned, respectively, withthe electrodes 106 a and 106 b on the bottom surface 114 of the sensorpod 100. In this configuration, the magnet 1206 a and the electrode 106a are attracted to one another, and the magnet 1206 b and the electrode106 b are similarly attracted to one another. While not shown in FIG.12C, a portion of a lapel, pocket or other article of apparel orclothing can be positioned between the magnets 1206 a and 1206 b and theelectrodes 106 a and 106 b. Nevertheless, the magnetic force between themagnets 1206 a and 1206 b and the electrodes 106 a and 106 b willmaintain the lapel adaptor 1200 in its folded position. The magnets 1206b and 1206 a can be permanent magnets. Alternatively, the magnets 1206 band 1206 a can include metal segments behind which permanent magnets arelocated to thereby magnetize the metal segments.

In the FIGS. and the above description, the sensor pod 100 was shown asand described as having an oval or elliptical circumferential shape. Inalternative embodiments the sensor pod 100 can have alternativecircumferential shapes, such as circular, rectangular, or square, butnot limited thereto. Where the sensor pod 100 has an alternativecircumferential shape, the elastic rings (e.g., 700 and 1207) describedherein, which are used to selectively attached the sensor pod 100 to anarticle of apparel or clothing, or to an lapel adaptor, can similarlyhave such an alternative circumferential shape.

The foregoing detailed description of the technology herein has beenpresented for purposes of illustration and description. It is notintended to be exhaustive or to limit the technology to the precise formdisclosed. Many modifications and variations are possible in light ofthe above teaching. The described embodiments were chosen to bestexplain the principles of the technology and its practical applicationto thereby enable others skilled in the art to best utilize thetechnology in various embodiments and with various modifications as aresuited to the particular use contemplated. It is intended that the scopeof the technology be defined by the claims appended hereto. Whilevarious embodiments have been described above, it should be understoodthat they have been presented by way of example, and not limitation. Itwill be apparent to persons skilled in the relevant art that variouschanges in form and detail can be made therein without departing fromthe spirit and scope of the invention. The breadth and scope of thepresent invention should not be limited by any of the above-describedexemplary embodiments, but should be defined only in accordance with thefollowing claims and their equivalents.

What is claimed is:
 1. A physiologic sensor pod comprising: a housing; afirst electrode on a bottom surface of the housing; a second electrodeon the bottom surface of the housing and spaced apart from the firstelectrode; a battery within the housing; a battery charging circuitwithin the housing; sensor circuitry within the housing, powered by thebattery, and adapted to selectively sense at least one physiologicsignal using at least one of the first and second electrodes; a resetdetection circuit within the housing; and a microcontroller within thehousing and adapted to control operation of the physiologic sensor pod;wherein the battery charging circuit is adapted to charge the batterywhen the first and second electrodes of the physiologic sensor pod areplaced in contact with first and second electrical contacts of acharging unit; wherein the reset detection circuit is adapted to outputa reset signal that is provided to and resets the microcontroller, whichcauses the physiologic sensor pod to be reset, when a voltage betweenthe first and second electrodes is greater than a reset threshold level.2. The physiologic sensor pod of claim 1, wherein the sensor circuitrycomprises: an electrocardiogram (ECG) sensor circuit within the housing,powered by the battery, and adapted to sense an ECG signal; wherein theECG sensor circuit is adapted to obtain an ECG signal while the firstand second electrodes are placed against a user's chest.
 3. Thephysiologic sensor pod of claim 2, further comprising: switch circuitrywithin the housing and electrically coupled to the first and secondelectrodes; and wherein the microcontroller within the housing ispowered by the battery and is adapted to control at least a portion ofthe switch circuitry; wherein when the switch circuitry is in a firstconfiguration the first and second electrodes are connected to thebattery charging circuit; and wherein when the switch circuitry is in asecond configuration, the first electrode is connected to a first inputof the ECG sensor circuit and the second electrode is connected to asecond input of the ECG sensor circuit.
 4. The physiologic sensor pod ofclaim 3, wherein the switch circuitry is in the first configuration bydefault.
 5. The physiologic sensor pod of claim 1, wherein the resetsignal, output by the reset detection signal, is provided to a reset pinof the microcontroller.
 6. The physiologic sensor pod of claim 1,wherein the charging unit, in response to a reset button of the chargingunit being pressed while the first and second electrodes of thephysiologic sensor pod are placed in contact with first and secondelectrical contacts of the charging unit, causes the voltage between thefirst and second electrodes to be greater than the reset thresholdlevel.
 7. The physiologic sensor pod of claim 1, wherein: the resetdetection circuit comprises a comparator that compares a voltageindicative of the voltage between the first and second electrodes to areference voltage indicative of the reset threshold level; and thecomparator outputs the reset signal when the voltage indicative of thevoltage between the first and second electrodes is greater than thereference voltage indicative of the reset threshold level.
 8. A methodfor use with a physiologic sensor pod that includes a housing includinga top surface, a bottom surface and a peripheral surface extendingbetween the top and bottom surfaces; a first electrode on the bottomsurface of the housing; a second electrode on the bottom surface of thehousing and spaced apart from the first electrode; a battery within thehousing; a battery charging circuit within the housing and adapted tocharge the battery when the first and second electrodes of thephysiologic sensor pod are placed in contact with first and secondelectrical contacts of a charging unit; sensor circuitry within thehousing, powered by the battery, and adapted to selectively sense atleast one physiologic signal using at least one of the first and secondelectrodes; and a microcontroller within the housing and adapted tocontrol operation of the physiologic sensor pod; the method comprising:comparing a voltage indicative of a voltage between the first and secondelectrodes to a reference voltage indicative of a reset threshold level;and resetting the microcontroller of the physiologic sensor pod when thevoltage indicative of the voltage between the first and secondelectrodes is greater than the reference voltage indicative of the resetthreshold level.
 9. The method of claim 8, wherein the sensor circuitrycomprises an electrocardiogram (ECG) sensor circuit within the housing,powered by the battery, and adapted to sense an ECG signal between thefirst and second electrodes, and wherein the physiologic sensor pod alsoincludes: switch circuitry within the housing and electrically coupledto the first and second electrodes; and a controller within the housing,powered by the battery, and adapted to control at least a portion of theswitch circuitry; the method further comprising: using the controller toselectively configure the switch circuitry in a first configuration anda second configuration, wherein in the first configuration the first andsecond electrodes are connected to the battery charging circuit, andwherein in the second configuration the first electrode is connected toa first input of the ECG sensor circuit and the second electrode isconnected to a second input of the ECG sensor circuit; wherein theresetting the physiologic sensor pod comprises resetting the controller;and wherein the controller can be a microcontroller.
 10. The method ofclaim 8, wherein: the physiologic sensor pod also includes amicrocontroller within the housing and adapted to control operation ofthe physiologic sensor pod; and wherein the resetting the physiologicsensor pod comprising provided a reset signal to a reset pin of themicrocontroller.
 11. The method of claim 8, further comprising: usingthe battery charging circuit to charge the battery when the first andsecond electrodes of the physiologic sensor pod are placed in contactwith first and second electrical contacts of a charging unit; causingthe voltage between the first and second electrodes to be greater thanthe reset threshold level, in response to a reset button of the chargingunit being pressed while the first and second electrodes of thephysiologic sensor pod are placed in contact with first and secondelectrical contacts of the charging unit.
 12. The method of claim 8,therein the resetting the physiologic sensor pod comprises: comparing avoltage indicative of the voltage between the first and secondelectrodes to a reference voltage indicative of the reset thresholdlevel; outputting a reset signal when the voltage indicative of thevoltage between the first and second electrodes is greater than thereference voltage indicative of the reset threshold level; and resettingthe physiologic sensor pod in response to the reset signal.
 13. Asystem, comprising: a physiologic sensor pod including a physiologicsensor pod housing including a top surface, a bottom surface and aperipheral surface extending between the top and bottom surfaces; afirst electrode on the bottom surface of the physiologic sensor podhousing; a second electrode on the bottom surface of the physiologicsensor pod housing and spaced apart from the first electrode; a batterywithin the physiologic sensor pod housing; a battery charging circuitwithin the physiologic sensor pod housing; sensor circuitry within thehousing, powered by the battery, and adapted to selectively sense atleast one physiologic signal using at least one of the first and secondelectrodes; a reset detection circuit within the physiologic sensor podhousing; and a microcontroller within the housing and adapted to controloperation of the physiologic sensor pod; a charging unit including acharging unit housing including a first electrical contact and a secondelectrical contact spaced apart from the first electrical contact; and avoltage regulator within the charging unit housing and adapted toselectively produce a voltage between the first and second electricalcontacts; wherein the battery charging circuit of the physiologic sensorpod is adapted to charge the battery when the first and secondelectrodes of the physiologic sensor pod are placed in contact withfirst and second electrical contacts of the charging unit; and whereinthe reset detection circuit of the physiologic sensor pod is adapted tooutput a reset signal that is provided to and resets themicrocontroller, which causes the physiologic sensor pod to be reset,when a voltage between the first and second electrodes is greater than areset threshold level.
 14. The system of claim 13, wherein the sensorcircuitry includes an electrocardiogram (ECG) sensor circuit within thehousing, powered by the battery, and adapted to sense an ECG signal; andwherein the ECG sensor circuit is adapted to obtain an ECG signal whilethe first and second electrodes are placed against a user's chest. 15.The system of claim 14, wherein the physiologic sensor furthercomprises: switch circuitry within the housing and electrically coupledto the first and second electrodes; wherein the microcontroller withinthe housing is powered by the battery and is adapted to control at leasta portion of the switch circuitry; wherein when the switch circuitry isin a first configuration the first and second electrodes are connectedto the battery charging circuit; and wherein when the switch circuitryis in a second configuration, the first electrode is connected to afirst input of the ECG sensor circuit and the second electrode isconnected to a second input of the ECG sensor circuit.
 16. The system ofclaim 13, wherein the reset signal, output by the reset detectionsignal, is provided to a reset pin of the microcontroller.
 17. Thesystem of claim 13, wherein: the charging unit includes a reset button;and the charging unit is adapted to cause the voltage between the firstand second electrical contacts, produced by the voltage regulator, to begreater than the reset threshold level, in response to the reset buttonof the charging unit being pressed.
 18. The system of claim 13, wherein:the reset detection circuit of the physiologic sensor pod comprises acomparator that compares a voltage indicative of the voltage between thefirst and second electrodes to a reference voltage indicative of thereset threshold level; and the comparator outputs the reset signal whenthe voltage indicative of the voltage between the first and secondelectrodes is greater than the reference voltage indicative of the resetthreshold level.
 19. The system of claim 13, wherein the charging unitis adapted to detect when the physiologic sensor pod is resting onand/or against the charging unit, and wherein the charging unit isadapted to produce no voltage between the first and second electricalcontacts when the physiologic sensor pod is not detected to be restingon and/or against the charging unit.
 20. The system of claim 19, whereinthe charging unit comprises a light source and a light detector thatcollectively operate as an optical proximity detector adapted to detectwhen the physiologic sensor pod is resting on and/or against thecharging unit.